Young children can infer information preferences from goals and recommend appropriate sources to others.

As adults, we intuitively understand how others' goals influence their information-seeking preferences. For example, you might recommend a dense book full of mechanistic details to someone trying to learn about a topic in-depth, but a more lighthearted book filled with surprising stories to someone seeking entertainment. Moreover, you might do this with confidence despite knowing few details about either book.

No guts, no glory: underestimating the benefits of providing children with mechanistic details.

Previous research shows that children effectively extract and utilize causal information, yet we find that adults doubt children's ability to understand complex mechanisms. Since adults themselves struggle to explain how everyday objects work, why expect more from children? Although remembering details may prove difficult, we argue that exposure to mechanism benefits children via the formation of abstract causal knowledge that supports epistemic evaluation. We tested 240 6-9 year-olds' memory for concrete details and the ability to distinguish expertise before, immediately after, or a week after viewing a video about how combustion engines work.

The neural bases of argumentative reasoning.

Most reasoning tasks used in behavioral and neuroimaging studies are abstract, triggering slow, effortful processes. By contrast, most of everyday life reasoning is fast and effortless, as when we exchange arguments in conversation. Recent behavioral studies have shown that reasoning tasks with the same underlying logic can be solved much more easily if they are embedded in an argumentative context.

Believing What You're Told: Politeness and Scalar Inferences.

The experimental pragmatics literature has extensively investigated the ways in which distinct contextual factors affect the computation of scalar inferences, whose most studied example is the one that allows "Some -ed" to mean . Recent studies from Bonnefon et al. (2009, 2011) investigate the effect of politeness on the interpretation of scalar utterances.

Vigilant conservatism in evaluating communicated information.

In the absence of other information, people put more weight on their own opinion than on the opinion of others: they are conservative. Several proximal mechanisms have been suggested to account for this finding. One of these mechanisms is that people cannot access reasons for other people's opinions, but they can access the reasons for their own opinions-whether they are the actual reasons that led them to hold the opinions (rational access to reasons), or post-hoc constructions (biased access to reasons).

Argumentation and the diffusion of counter-intuitive beliefs.

Research in cultural evolution has focused on the spread of intuitive or minimally counterintuitive beliefs. However, some very counterintuitive beliefs can also spread successfully, at least in some communities-scientific theories being the most prominent example. We suggest that argumentation could be an important factor in the spread of some very counterintuitive beliefs.

The Selective Laziness of Reasoning.

Reasoning research suggests that people use more stringent criteria when they evaluate others' arguments than when they produce arguments themselves. To demonstrate this "selective laziness," we used a choice blindness manipulation. In two experiments, participants had to produce a series of arguments in response to reasoning problems, and they were then asked to evaluate other people's arguments about the same problems.

Arguments, more than confidence, explain the good performance of reasoning groups.

In many intellective tasks groups consistently outperform individuals. One factor is that the individual(s) with the best answer is able to convince the other group members using sound argumentation. Another factor is that the most confident group member imposes her answer whether it is right or wrong.

Time-dependent release of growth factors from implant surfaces treated with plasma rich in growth factors.

Plasma rich in growth factors (PRGFs) technology is an autologous platelet-rich plasma approach that provides a pool of growth factors and cytokines that have been shown to increase tissue regeneration and accelerate dental implant osseointegration. In this framework, the spatiotemporal release of growth factors and the establishment of a provisional fibrin matrix are likely to be key aspects governing the stimulation of the early phases of tissue regeneration around implants. We investigated the kinetics of growth factor release at implant surfaces functionalized either with PRGFs or platelet-poor plasma and correlated the results obtained with the morphology of the resulting interfaces.

Evaluation of alginate microspheres for mesenchymal stem cell engraftment on solid organ.

Mesenchymal stem cells (MSCs) may be used as a cell source for cell therapy of solid organs due to their differentiation potential and paracrine effect. Nevertheless, optimization of MSC-based therapy needs to develop alternative strategies to improve cell administration and efficiency. One option is the use of alginate microencapsulation, which presents an excellent biocompatibility and an in vivo stability.

Characterization of monoamine oxidases in mesenchymal stem cells: role in hydrogen peroxide generation and serotonin-dependent apoptosis.

Early death of grafted bone marrow mesenchymal stem cells (MSCs) represents a major limit to their use in cell therapy of solid organs. It is well known that oxidative stress plays a major role in cell death. We have recently shown that the serotonin-degrading enzyme monoamine oxidase A (MAO-A) generates large amount of hydrogen peroxide (H2O2) responsible for cell apoptosis.

Mesenchymal stem cells promote matrix metalloproteinase secretion by cardiac fibroblasts and reduce cardiac ventricular fibrosis after myocardial infarction.

Recent studies showed that mesenchymal stem cells (MSCs) transplantation significantly decreased cardiac fibrosis; however, the mechanisms involved in these effects are still poorly understood. In this work, we investigated whether the antifibrotic properties of MSCs involve the regulation of matrix metalloproteinases (MMPs) and matrix metalloproteinase endogenous inhibitor (TIMP) production by cardiac fibroblasts. In vitro experiments showed that conditioned medium from MSCs decreased viability, alpha-smooth muscle actin expression, and collagen secretion of cardiac fibroblasts.

Ex vivo pretreatment with melatonin improves survival, proangiogenic/mitogenic activity, and efficiency of mesenchymal stem cells injected into ischemic kidney.

Bone marrow mesenchymal stem cells (MSCs) have shown great potential in cell therapy of solid organs. Approaches to improving the ability of grafted MSCs to survive and secrete paracrine factors represent one of the challenges for the further development of this novel therapy. In the present study, we designed a strategy of ex vivo pretreatment with the pineal hormone melatonin to improve survival, paracrine activity, and efficiency of MSCs.

[Spatial orienting of attention: a study of reaction time during pointing movement].

Aim: The aim of this study was to investigate how advance information both explicit and implicit provided prior to movement may affect the spatial orientation and the internal attention control processes in normal adult subjects. The originality of this work compared to the test of Posner, lies essentially in the methodology used to study the attentional systems. The use of three procedures of reaction time (RT) allowed us to study the setting concerned of the specific and non-specific components of the attention in the motor preparation.

[Effects of spatial orientation on attention reaction time during pointing movement towards visual direction].

In the present study, it was consequently proposed to investigate how the spatial orientation of attention made by the explicit and implicit components of advance information, affected the reaction time (RT) performances. Subjects performed a simple RT task with an orientation cue and two choice RT situations, the one with a neutral cue and the other with a primed cue. The motor task to be performed consisted of pointing towards a visual target.

[Effects of advance information given by sensory cues on the duration and precision of a pointing movement in Parkinson's disease].

The aim of the present study was to investigate Parkinsonians' ability to process and use the explicit and implicit advance information available about a motor task they are preparing to perform. For this purpose, the performances of 13 Parkinsonians were compared with those of 11 control subjects in a double stimulus reaction time task. The explicit information was provided by a preparatory auditory signal (S1), and the implicit information was conveyed by the probability that the imperative signal (S2) would be consistent with S1 in a given series of trials.

The use of advance information for motor preparation in Parkinson's disease: effects of cueing and compatibility between warning and imperative stimuli.

The ability of 13 Parkinsonian patients and 11 age-matched control subjects to process and use two components of the information given prior to a voluntary movement was studied using reaction time (RT) tasks. This advance information about the direction of a pointing movement was given using a double stimulation paradigm with an auditory warning signal (WS) which occurred prior to a visual imperative signal (IS). The first component of the information was given by the WS at the beginning of each trial, and the second component was the WS-IS compatibility during series of trials.

Spatio-temporal and kinematic analysis of pointing movements performed by cerebellar patients with limb ataxia.

Three patients with cerebellar limb ataxia and three age-matched controls performed arm-pointing movements towards a visual stimulus during an experimental procedure using a double-step paradigm in a three-dimensional space. Four types of trajectories were defined: P1, single-step pointing movement towards the visual stimulus in the initial position S1; P2, double-step pointing movement towards S1; P3, double-step straight pointing movement towards the second position S2; and P4, double-step pointing movement towards S2 with an initial direction towards S1. We found that the cerebellar patients, as well as the controls, were able to modify their motor programs, but with impaired timing, severe anomalies in the direction and amplitude of the changed movement trajectories and alteration of the precision of the pointing movements.

Responses of tonically discharging neurons in the monkey striatum to primary rewards delivered during different behavioral states.

In the primate striatum, the tonically discharging neurons respond to conditioned stimuli associated with reward. We investigated whether these neurons respond to the reward itself and how changes in the behavioral context in which the reward is delivered might influence their responsiveness. A total of 286 neurons in the caudate nucleus and putamen were studied in two awake macaque monkeys while liquid reward was delivered in three behavioral situations: (1) an instrumental task, in which reward was delivered upon execution of a visually triggered arm movement; (2) a classically conditioned task, in which reward was delivered 1 s after a visual signal; (3) a free reward situation, in which reward was delivered at irregular time intervals outside of any conditioning task.

Responses of tonically discharging neurons in monkey striatum to visual stimuli presented under passive conditions and during task performance.

To test whether the responsiveness of tonically discharging neurons from monkey striatum is dependent on the motor or rewarding features of the conditioned stimuli, we studied the responses of these neurons to visual stimuli presented under two behavioral conditions: during an operant task in which the stimulus triggered a movement to obtain a reward, and in a non-performing state in which the stimulus was consistently followed by a reward outside of a task. Most of the neurons tested (110/158) responded to the stimuli presented in both conditions, while a relatively small number of neurons (35/158) showed selective responses in one or other of the conditions. A gradual disappearance of neuronal responses occurred in the passive state when presenting a stimulus which was never followed by reward.

A defective control of small-amplitude movements in monkeys with globus pallidus lesions: an experimental study on one component of pallidal bradykinesia.

The effects of globus pallidus (GP) lesion were examined in two monkeys trained to perform a visually guided pointing movement in simple and choice reaction time tasks involving small and large amplitude movements. The reaction time (RT) and the movement time (MT) were measured. The Y-axis error (EY) was also analyzed in order to assess the movement accuracy.

Quantitative behavioral study of the acute and long-term effects of two-stage bilateral 6-OHDA-induced lesions of the nigrostriatal dopaminergic system in monkeys.

Bilateral lesions of the nigrostriatal dopaminergic system (2-stage lesions separated by 5-6 months) were induced in 3 monkeys trained to initiate forelimb-reaching movements toward a visual target. After each lesion, analysis of the task performance over several months of regular testing showed that the latency to initiate the movement was permanently prolonged in monkeys showing 90% or more striatal dopamine depletion, whereas animals with less severe depletion completely recovered the task performance. Several months after a unilateral nigrostriatal damage, a lesion on the other side produced impairments only on the side of the body contralateral to that second lesion and did not reinstate the deficits on the side previously affected by the first lesion.

Planning and execution of pointing movements in cerebellar patients.

Twelve patients with cerebellar dysfunction including a limb ataxia and 12 age-matched controls performed pointing movements with an arm. In one condition, the task was a simple reaction time (RT) movement directed toward a spatially defined target. The other two conditions involved choice tasks in which the amplitude and direction of movement were varied.

Bilateral and side-related reaction time impairments in patients with unilateral cerebral lesions of a medial frontal region involving the supplementary motor area.

Human subjects (nine patients with unilateral brain lesions of a medial frontal region involving the supplementary motor area, SMA, and 10 controls) performed two reaction time (RT) tasks in response to the presentation of a luminous signal: an aimed movement towards a spatially defined target involving hand lifting and pointing with the index finger, and a no-aimed movement consisting of the hand lifting phase completed by the stabilization of the limb posture without any pointing. When compared with controls, the patients exhibited a bilateral RT increase which was more pronounced in the hand contralateral to the lesion. Moreover, comparison between the two tasks showed that this contralateral RT impairment was more marked in the no-aiming than in the aiming task.

Methods of motor performance evaluation: application to a primate model for basal ganglia pathology.

In studies on the motor impairments induced in monkeys by performing lesions of various kinds on the central nervous system, it is necessary to be able to exactly quantify the motor deficits. The battery of tests described in the present paper (simple and choice reaction-time procedures, goal-directed pointing movement, digital manipulation task) provide a systematic means of analysing the motor performances involving movement control. Central nervous dysfunction can be induced by either reversibly or permanently excluding specific structures.